Second, while this book concerns the idea of `emergent' spacetime as it arises in QG, one of our key concerns has already arisen in discussions of a different kind of spacetime emergence. The quantum mechanical wavefunction of \(N\)  particles is not a function in ordinary space, but of the positions of all the particles: \(\Psi (x_1,y_1,z_1; x_2,y_2,z_2; \dots ; x_N,y_N,z_N)\) . Thus \(\Psi \)  lives in `configuration' space, in which there are three dimensions for each particle. [1]} has argued that we should take the wavefunction `seriously' as the ontology of the theory, and conclude that configuration space is more fundamental than regular space—that the three dimensions of experience are mere appearances of the \(3N\)  dimensions of reality. Whatever the merits of that view, the general idea has been attacked by Tim [2]}. In particular he argues as follows: one might
